Port Elizabeth: The absence of Kagiso Rabada for the rest of the series can't hurt but Darren Lehmann says Australia must perform better with the bat, regardless of who is fronting the South African bowling attack.

Steve Smith's Australians were travelling to Cape Town on Tuesday, a day after a six-wicket defeat that left the series level at 1-1 at the halfway mark.

Banned: South African tearaway Kagiso Rabada will miss the rest of the series. Photo: AP

There were no celebrations for the tourists in the Eastern Cape but it could be understood if there was a wry smile or two about South Africa's loss of Rabada to suspension for the final two matches at Newlands and the Wanderers.

Arguably the best fast bowler in the world, the fact the 22-year-old won't be steaming in and bending the ball both ways is surely a plus for Australia's ambition to leave the continent with their unbeaten track record here since South Africa's readmission intact.

However, Australian coach Lehmann says the visitors will be more focused on addressing their batting woes after a few days' break than getting carried away about not having to face Rabada again.

"It's never good seeing fantastic bowlers out of series," Lehmann said. "They're going to miss him, there is no doubt about it, but they've got some pretty good bowlers that are back-ups. For us it doesn't matter who plays. We've got to play and bat better than than first two Test matches.

"That's the difference at the moment. AB [de Villiers] went on and got [126 not out] and that hurts you in this sort of format when the series is going to be so tight. Runs are going to be at a premium against two quality bowling attacks."

Smith, for once, is guilty himself of coming up short, although in a roundabout way he has done the team a big favour by being on the receiving in of the brush of shoulders from Rabada that resulted in the paceman's two-match ban.

That incident occurred after Rabada knocked him over in the first innings at St George's Park, while Smith has been out on the three other occasions to the left-arm orthodox spin of Keshav Maharaj (twice) and Dean Elgar.

It wouldn't matter if it was an underarm bowler who got him out if he was scoring the kind of runs that de Villiers has been and with such apparent ease. But averaging 32.5 for the series is underwhelming for a batsman of Smith's calibre and he knows it.

"He's disappointed with his output," Lehmann said. "He sets his standards so high, so we expect him to come back strong in the last two Test matches and have a real impact."

Lehmann also weighed on the ICC disciplinary system after Mitchell Marsh joined Rabada in being reported at St George's Park, bringing to six the number of charges levelled at players for breaches of the code of conduct in nine days of this series.

South Africa's penchant for going down swinging with the match referee, contesting Rabada's level-two charge over physical contact made with Smith at a hearing, and after that failed, seeking legal advice over whether to appeal.

Proteas captain Faf du Plessis questioned the consistency of the system, highlighting the fact that Rabada had received the same number of demerit points - three - for that incident as David Warner did for his heated altercation with Quinton de Kock at Kingsmead and suggesting the latter was a more serious offence.

The Australians have tended to take their medicine when it comes to being sanctioned by a match referee. Lehmann said he had no issues with the penalty system.

"We normally put up our hand and move on and that's just the way it's been," Lehmann said. "They give you a charge overnight and you make a decision from there, and that's how it's been since I've been involved anyway. Each country to their own really on that one.

"That's the ICC. They deal with the codes and demerit points and that's how it is. From my point of view, we've had no issues with it in the past."

Australia are "reasonably confident" Mitchell Marsh will be able to overcome a groin strain in time for the third Test, which starts on Thursday week.

"But we'll see over the next couple of days," Lehmann said. "Medical staff will have a look at him and assess him and then make a call from there. We're hopeful for the next Test."